Add testcase for #394

tests/configs/issue394.conf

@@ -0,0 +1,4 @@
+fading = true;
+fade-in-step = 1;
+fade-out-step = 0.01;
+shadow = true;

tests/run_tests.sh

@@ -16,3 +16,4 @@ eval `dbus-launch --sh-syntax`
 ./run_one_test.sh $exe configs/issue314.conf testcases/issue314_3.py
 ./run_one_test.sh $exe /dev/null testcases/issue299.py
 ./run_one_test.sh $exe configs/issue465.conf testcases/issue465.py
+./run_one_test.sh $exe configs/issue394.conf testcases/issue394.py

tests/testcases/common.py

@@ -28,6 +28,11 @@ def set_window_class(conn, wid, name):
     str_type = to_atom(conn, "STRING")
     conn.core.ChangePropertyChecked(xproto.PropMode.Replace, wid, prop_name, str_type, 8, len(name), name).check()
 
+def set_window_size(conn, wid, width, height):
+    value_mask = xproto.ConfigWindow.Width | xproto.ConfigWindow.Height
+    value_list = [width, height]
+    conn.core.ConfigureWindowChecked(wid, value_mask, value_list).check()
+
 def find_picom_window(conn):
     prop_name = to_atom(conn, "WM_NAME")
     setup = conn.get_setup()

tests/testcases/issue394.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+
+import xcffib.xproto as xproto
+import xcffib
+import time
+from common import set_window_name, set_window_size
+
+conn = xcffib.connect()
+setup = conn.get_setup()
+root = setup.roots[0].root
+visual = setup.roots[0].root_visual
+depth = setup.roots[0].root_depth
+
+# issue 394 is caused by a window getting a size update just before destroying leading to a shadow update on destroyed window.
+wid = conn.generate_id()
+print("Window id is ", hex(wid))
+
+# Create a window
+conn.core.CreateWindowChecked(depth, wid, root, 0, 0, 100, 100, 0, xproto.WindowClass.InputOutput, visual, 0, []).check()
+
+# Set Window name so it doesn't get a shadow
+set_window_name(conn, wid, "Test Window")
+
+# Map the window
+print("mapping")
+conn.core.MapWindowChecked(wid).check()
+
+time.sleep(0.5)
+
+# Resize the window and destroy
+print("resize and destroy")
+set_window_size(conn, wid, 150, 150)
+conn.core.DestroyWindowChecked(wid).check()
+
+time.sleep(0.5)